減少JavaScript迭代

Question

現在，我正在使用javascript開發時間軸程序。 當我單擊每個班級時，由於每個班級均為2小時課程，因此應將其着色為帶有2個塊的時間軸。

每個時間軸表都有id（例如，星期一的第一堂課有=“ mon1”，而生日的第二堂課有'fri2'

這是我的代碼。 而且效果很好。 但我想知道如何減少代碼。

let timelineColor = getRamdomColor();
let clickDay;
let clickDay1;

for (i = 0; i < dayArray.length; i++) {
    if (dayArray[i] === 'monday') {
        clickDay = 'mon' + timeArray[i];
        let table = document.getElementById(clickDay);
        table.style.backgroundColor = timelineColor;
        clickDay1 = 'mon' + (Number(timeArray[i]) + 1);
        console.log(clickDay1);
        let table1 = document.getElementById(clickDay1);
        table1.style.backgroundColor = timelineColor;
    } else if (dayArray[i] === 'tuesday') {
        clickDay = 'tue' + timeArray[i];
        let table = document.getElementById(clickDay);
        table.style.backgroundColor = timelineColor;
        clickDay1 = 'tue' + (Number(timeArray[i]) + 1);
        let table1 = document.getElementById(clickDay1);
        table1.style.backgroundColor = timelineColor;
    } else if (dayArray[i] === 'wednesday') {
        clickDay = 'wed' + timeArray[i];
        let table = document.getElementById(clickDay);
        table.style.backgroundColor = timelineColor;
        clickDay1 = 'wed' + (Number(timeArray[i]) + 1);
        let table1 = document.getElementById(clickDay1);
        table1.style.backgroundColor = timelineColor;
    } else if (dayArray[i] === 'thursday') {
        clickDay = 'tur' + timeArray[i];
        let table = document.getElementById(clickDay);
        table.style.backgroundColor = timelineColor;
        clickDay1 = 'tur' + (Number(timeArray[i]) + 1);
        let table1 = document.getElementById(clickDay1);
        table1.style.backgroundColor = timelineColor;
    } else if (dayArray[i] === 'friday') {
        clickDay = 'fri' + timeArray[i];
        let table = document.getElementById(clickDay);
        table.style.backgroundColor = timelineColor;
        clickDay1 = 'fri' + (Number(timeArray[i]) + 1);
        let table1 = document.getElementById(clickDay1);
        table1.style.backgroundColor = timelineColor;
    }
}

Answer 1

您實際上根本不需要if語句。 設置一個將您的全天名稱與短日名稱相關聯的地圖，然后進行查找：

let timelineColor = getRamdomColor();
let clickDay;
let clickDay1;

var dayMap = {
    'monday'   : 'mon',
    'tuesday'  : 'tue',
    'wednesday': 'wed',
    'thursday' : 'tur',
    'friday'   : 'fri'
};

for (var i = 0; i < dayArray.length; i++) {
    let shortDayName = dayMap[dayArray[i]];
    clickDay = shortDayName + timeArray[i];
    let table = document.getElementById(clickDay);
    table.style.backgroundColor = timelineColor;
    clickDay1 = shortDayName + (Number(timeArray[i]) + 1);
    console.log(clickDay1);
    let table1 = document.getElementById(clickDay1);
    table1.style.backgroundColor = timelineColor;
}

Answer 2

您可以使用switch語句而不是多個if-elseif語句：

let timelineColor = getRamdomColor();

for (i = 0; i < dayArray.length; i++){
  let day;

  switch (dayArray[i]){
    case 'monday': day = 'mon'; break;
    case 'tuesday': day = 'tue'; break;
    case 'wednesday': day = 'wed'; break;
    case 'thursday': day = 'tur'; break;
    case 'friday': day = 'fri'; break;
  }

  // I moved these variables into the loop too
  let clickDay = day + timeArray[i];
  let clickDay1 = day + (Number(timeArray[i]) + 1);

  let table = document.getElementById(clickDay);
  let table1 = document.getElementById(clickDay1);

  table.style.backgroundColor = timelineColor;
  table1.style.backgroundColor = timelineColor;
}